Okay, I asked the question wrong! I was almost asleep when I did it so please forgive me.
The question I have has nothing to do with efficiency. What I wondered about was the load of the speakers; or why are some speakers designed at a nominal 8 ohm while others drop as low as two or even one ohm. The lower being more difficult to drive. Are these differences based on the individual drivers or on crossover design? Why doesn't everyone design their speaker to be a nominal 8 ohm, or higher? What are the benefits of 4, 2, or even 1 ohm speakers?
The question I have has nothing to do with efficiency. What I wondered about was the load of the speakers; or why are some speakers designed at a nominal 8 ohm while others drop as low as two or even one ohm. The lower being more difficult to drive. Are these differences based on the individual drivers or on crossover design? Why doesn't everyone design their speaker to be a nominal 8 ohm, or higher? What are the benefits of 4, 2, or even 1 ohm speakers?